Growth sector dependence and mechanism of stress formation in epitaxial diamond growth

Stress generation in epitaxial diamond growth was investigated by μ-Raman spectroscopy and high resolution x-ray diffraction. Intrinsic stress could be varied systematically from compressive to tensile covering a huge range of 5 GPa. The temperature-stress curve for growth on {111}-sectors as compared to {001} shows a shift of −200 °C or +2 GPa. A crucial role of hydrogen in the stress formation process is excluded. Due to the absence of grain boundaries, a model is proposed which is based on the “effective climb” of individual dislocations. The controlled generation of stress profiles offers a powerful concept for strengthening diamond mechanical devices.